Reference is made to the present inventor's copending U.S. patent applications (1) Ser. No. 07/197,620, entitled "Marine Drive With Improved Propeller Mounting", and (2) Ser. No. 07/197,452, entitled "Marine Drive With Improved Propeller Shaft Bearing Carrier Arrangement"; both being filed on even date herewith.
This invention relates to a mounting device between a rotary shaft and a hub or other member mounted thereon and driven thereby, and more particularly to marine drive devices including a propeller shaft which rotatably drives a hub-mounted propeller thereon. When applied to the marine field, the invention can be utilized in both outboard motor and stern drive applications.
Referring to the above-named copending applications, it is desirable to mount one or more propellers on a propeller shaft in such a manner that shaft bearings and other elements can be brought rearwardly into the propellers as far as possible. The sets of mating conical surfaces described in the above first-named copending application serve this purpose. In some instances, however, it may be desirable to utilize a construction other than mating conical surfaces, such as when a marked change in shaft diameter is not preferable.
It is an object of the present invention to provide a mounting device between a rotatable shaft and driven hub or the like mounted thereon which permits axial compaction of the elements in a simple and efficient manner without major changes in the shaft diameter.
In accordance with the various aspects of the invention, and as applied to a marine drive for a boat, the drive includes a longitudinally extending propeller shaft which concentrically carries the hub of a propeller at the aft end of the shaft, with the shaft serving to rotatably drive the hub. The shaft is provided with a threaded outer peripheral portion at its end. The hub is provided with a rearwardly disposed annular flange and an annular rearwardly facing recess having a threaded outer periphery. A dual-threaded nut is removably disposed within the hub recess. The outer nut threads engage the hub threads, while the inner nut threads engage the threads of the propeller shaft. A device is provided for securing the nut against threadable rotation in its mounting. The inventive concepts may be utilized with a single or dual propeller system or any other hub and shaft connection.